The present disclosure relates to an image forming apparatus employing a developing method of supplying developer from a developer carrier carrying a layer of magnetized filaments to an image carrier carrying an electrostatic latent image.
In an image forming apparatus employing an electrophotographic method, such as a copier, printer or facsimile machine, developer is supplied from a developing roller to an electrostatic latent image formed on a photosensitive drum to develop the electrostatic latent image, thereby forming a toner image on the photosensitive drum. A development bias is applied to the developing roller. In some cases, the development bias includes an alternating current voltage and a direct current voltage that are superposed on each other. In order to set an appropriate development bias in such a case, there is known a technology of detecting a leakage voltage between the photosensitive drum and the developing roller.